The field of the invention pertains to plastic bottles and, in particular, to bottles for human or animal food products and consumables and for pharmaceutical capsules, pills and tablets. Such bottles, after filling and capping, are equipped with a shrink-fit plastic band over the cap and into the neck of the bottle. The top of the bottle is formed with a circumferential small bead or ring located just below the spiral thread on the bottle. The plastic band is shrunk-fit over the cap and into the neck below the circumferential bead.
The purpose of the plastic band is to prevent uncapping of the bottle without breaking the band. The band normally splits as the cap is unscrewed from the bottle. Thus, any prior removal of the cap is immediately exposed. Unfortunately, the plastic band material possesses sufficient elongation that splitting is not assured when the cap is removed from bottles with standard small beads.
The likelihood of failure to split is further compounded by the use of both standard caps and oversize caps such as two piece "child-resistant" caps with the same size bottle necks and threads. The exterior diameter and skirt length of the two piece "child-resistant" cap are considerably larger than the standard cap. As a result the circumferential bead on the top lies within the skirt. The plastic shrink-fit band placed thereover is substantially, if not completely, ineffective in splitting when the cap is removed because the shrinkage below the skirt and circumferential bead is insufficient to tightly grasp the bead.
Illustrated in FIGS. 1, 2 and 3 below are three bottles with "child-resistant" caps thereon and plastic seals thereover. In FIG. 1 the circular bead has a diameter substantially equal to or smaller than the spiral thread. With the "child-resistant" cap the bead is under the skirt as shown. In FIG. 2 the bottle has a bead larger in diameter than the spiral thread, however, the bead is again covered by the skirt of the "child-resistant" cap. In FIG. 3 the bead includes a shoulder thereover with the bead just below the skirt of the "child-resistant" cap. The latter two bottles are of designs developed and currently available from applicant's company. The first bottle is conventional in the industry and the bead of the first bottle is inadequate to assure splitting of the plastic band upon opening of the cap.
Despite the use for many years of shrink-fit plastic bands as tamper indicators on bottles, the failure of the bands to split when the cap is removed continues to be an unsolved problem.